International Journal of Foreign Language Teaching 2(1): 9. 2006
Contrary to semi-popular opinion, the Comprehension Hypothesis does not forbid the use of the first language in the second language classroom. It does, however, provide guidelines. It predicts that the use of the first language will help second language development if it results in more comprehensible input, and will hurt second language development when it results in less comprehensible input.
Providing Background Knowledge
The first language helps when it provides background knowledge that functions to make second language input more comprehensible. This can happen in several ways:
It happens when the first language is used to provide background knowledge through discussion or reading. When teachers know that a topic needs to be discussed in class that is unusually complex or unfamiliar, a short presentation or set of readings in the first language can be of great help. A few minutes or a page or two on relevant aspects of the history of Mexico, for example, can transform a discussion of Cortez from one that is opaque to one that is transparent. This kind of background is, of course, most useful when teachers know that all or nearly all students will require it.
Bilingual education relies on the same principle: In bilingual programs, students are given background knowledge in the first language in order to make subsequent instruction delivered in the second language more comprehensible (Krashen, 1996).
The first language can also help when it is used during a lesson as a quick explanation. Comprehension difficulties can arise in unpredictable places and students differ in their need for background knowledge. The first language can be used as needed for quick explanations in the middle of discussions when some students are having trouble, and when it is not easy to paraphrase and use other means of providing context.
There is also nothing wrong with providing a quick translation for a problematic word that is central to a discussion. Providing the translation may or may not contribute very much to the acquisition of the meaning of the translated word, but it can help make the entire discussion more comprehensible.
The first language is misused when teachers provide so much information that there is no reason to continue the discussion in the second language.
It is also misused when teachers provide so many brief explanations and translations that it is difficult to keep track of the message. If this intervention is considered to be necessary, the topic may not be right. It has been hypothesized that the acquirer needs to be so interested in the message (or “lost in the book”) that he or she temporarily “forgets” that the message is in another language. When translations are excessive, the spell is broken.
Krashen, S. 1996. An overview of bilingual education. Bilingual Basics. Winter/Spring: 1-5.